I made a sculpture in Scuptris then Imported it into MeshLab to paint and export as .WRL. When I uploaded the sculpture it came out to be around $80!

I go to looking into the pricing and found that if I make it hallow that will help.

So here's my dilemma. I really don't want to have to repaint it all over again, but I don't know how to make a hole in the top of it in MeshLab. So if you can tell me how to accomplish this I would GREATLY appreciate it!

Someone more MeshLab knowledgeable than me might be able to post a MeshLab method for incoporating a hole, however as far as I know MeshLab is software for manipulating a mesh rather than a full-on editor. To add a hole to make the outside skin and inside skin into a hollow watertight model, you need to save the meshes from MeshLab and then use different software to put the hole in, either as a boolean or direct mesh editing.

To make a hole in blender to join the exterior and interior wall, select you object. Add another object(in this case I used a cylinder).
The connector between the outer and inner wall can be as tiny as you want. Its not a to drain unused material, it just alerts the 3D printer walls are there.
Do some scaling on the cylinder, make it long enough to intersect the two walls.Place it where you want the hole to be.
In edit mode, select all on the target object, change quads to tris(Cntrl T). Repeat for the hole maker(skinny cylinder). When you use the boolean modifier, it loves tris, less hassle for the computer.
Now select the target object, open up the boolean modifier,(select from modifier menu),
Select difference. Under object on that menu, click on the cube icon, select the name of the hole maker. Apply. You should now have both the outer wall and inner wall connected by a open ended cylinder, thus a hole.
Netfabb basic is good to check that the object is manifold, plus a volume measurement.
Blender versions 2.5 thru 2.63 have a modifier called solidify, where you can set exactly the thickness of the wall.(NICEY!) plus blender can be asked to search for non manifold meshes.
Any help you need with blender, go to # Blender channel on Freenode.net.

Have any questions regarding Blender, and need fast answers, you are always welcome at the IRC Server Freenode, channel #blender. As a bonus, several there have experience in modelling for 3D prints.

To make a hole in blender to join the exterior and interior wall, select you object. Add another object(in this case I used a cylinder).
The connector between the outer and inner wall can be as tiny as you want. Its not a to drain unused material, it just alerts the 3D printer walls are there.
Do some scaling on the cylinder, make it long enough to intersect the two walls.Place it where you want the hole to be.
In edit mode, select all on the target object, change quads to tris(Cntrl T). Repeat for the hole maker(skinny cylinder). When you use the boolean modifier, it loves tris, less hassle for the computer.
Now select the target object, open up the boolean modifier,(select from modifier menu),
Select difference. Under object on that menu, click on the cube icon, select the name of the hole maker. Apply. You should now have both the outer wall and inner wall connected by a open ended cylinder, thus a hole.
Netfabb basic is good to check that the object is manifold, plus a volume measurement.
Blender versions 2.5 thru 2.63 have a modifier called solidify, where you can set exactly the thickness of the wall.(NICEY!) plus blender can be asked to search for non manifold meshes.
Any help you need with blender, go to # Blender channel on Freenode.net.

I never did all that, I just deleted the some faces and used the solidify modifier you speak of to make my items.

I learned a long time ago the wisest thing I can do is be on my own side, be an advocate for myself and others like me. -Maya Angelou
michael@shapeways.com Community Advocate

The method you suggested works superb. I just hate to deface a mesh removing larger than necessary faces, then using solidify mod. With my method, at least you can drill between the walls at a spot that less noticeable. But with you a better modeler than I am, by far, I am not going to argue. I guess to each his/her own.

Have any questions regarding Blender, and need fast answers, you are always welcome at the IRC Server Freenode, channel #blender. As a bonus, several there have experience in modelling for 3D prints.